Let CreateInstance/CreateSet directly work on a matching constructor instead of relying on public fields or properties

[AroglDarthu]

I have a situation where my support model looks like this (reason for this setup is that I also need specific json serialization/deserialization):

public class FirstConcreteThingy : AbstractThingy<FirstConcreteContent>
{
    public FirstConcreteThingy(Guid x, string name, DateTimeOffset modifiedAt)
    {
        ModifiedAt = modifiedAt;
        Content = new FirstConcreteContent(x, name);
    }
}

public abstract class AbstractThingy<T>
{
    public DateTimeOffset ModifiedAt { get; set; }
    public T Content { get; set; }
}

The CreateInstance helper correctly identifies the constructor and my table has the three columns which match the constructor parameters.
However, the helper does not directly map from the table to these parameters. It expects public properties (or fields) to be available as well and then fills in the constructor parameters based on these properties.

So in my case only the ModifiedAt gets a value, although all data is available in the table.

I would be happy to contribute a PR for this feature. Please let me know if this feature fits your views around the table helpers, specificly CreateTheInstanceWithTheValuesFromTheTable.

[AroglDarthu]

I implemented a workaround for now, which is quite easy to make, but it feels a bit convoluted.
By adding a nested class ConstructorParameters with public properties matching the constructor and then providing a StepArgumentTransformation like this:

    public class FirstConcreteThingy : ...
    {
        internal sealed class ConstructorParameters
        {
            public Guid X { get; set; }
            public string Name { get; set; } = null!;
            public DateTimeOffset ModifiedAt { get; set; }

            public object[] ToArray()
            {
                return [X, Name, ModifiedAt];
            }
        }
 
        ...
    }

    [StepArgumentTransformation]
    public FirstConcreteThingy TransformInstance(Table table)
    {
        var constructor = typeof(FirstConcreteThingy).GetConstructors()[0];
        var parameters = table.CreateInstance<FirstConcreteThingy.ConstructorParameters>();

        return (FirstConcreteThingy)constructor.Invoke(parameters.ToArray());
    }

[gasparnagy]

This is interesting. I haven't considered that, but that would be a good use-case.

Could you please try to make something in a prototype-level first and send it as a draft PR, so that we can see the potential issues and see how the naming and the API should look like.

[AroglDarthu]

See #488. Forgot to mark it as draft though :-/

edit: found the convert to draft option, so now it is a draft